PHYSICAL EVIDENCE

Forensic Science Project

Activity Objectives

During this activity you should be able to do:

• Observe and record the characteristics of various samples of cloth fibers, stains on cloth and hair
• Use similarities and differences in collected samples as a means of identification

Procedure

Part 1 - Cloth Fibers

• Obtain a sample of cloth
• Carefully observe and draw the cloth as seen with your eye
• Observe and draw the same cloth as seen using a hand lens or microscope. Record a description of the cloth including colour, texture, arrangement of fibers and any other observable features

Part 2 - Stains

• Obtain three different pieces of cloth. Each piece should be numbered and will have a different stain on it. You will be asked to observe the stain under the microscope and describe your observations. Make a table to record your diagrams and observations.
• Observe each stain with the hand lens or microscope and record any observations of the stain that you have seen.
• Obtain a sample of the unknown stain. Make sure you record the letter of the stain
• Observe the unknown stain with the hand lens or microscope and identify which known stain matches the unknown stain
• Provide two pieces of evidence that supports your choice

Part 3 - Hair Analysis

• Obtain three samples of hair - one of your own and two from others in your class.
• Make a wet mount slide of one of the hairs
• Using the microscope observe the hair and record its characteristics including colour, thickness, texture and any unique characteristics like split ends. Don't forget to observe both ends of the hair as well
• Repeat this procedure for the other two hair samples and note and record any differences

Reflections on the Activity

1. If you were the forensic scientist at the scene of a crime, what other kinds of physical evidence would you collect that might be useful in the investigation?
2. Explain how physical evidence collected at the science of a crime could be used to assist in an arrest and conviction of a suspect.

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